像这样的东西
<html>
<body style="height:100%; width:100%">
<div id="header" style="position:absolute; top:0px; left:0px; height:200px; right:0px;overflow:hidden;">
</div>
<div id="content" style="position:absolute; top:200px; bottom:200px; left:0px; right:0px; overflow:auto;">
</div>
<div id="footer" style="position:absolute; bottom:0px; height:200px; left:0px; right:0px; overflow:hidden;">
</div>
</body>
</html>